Paper spray ionization

Paper spray ionization is a technique used in mass spectrometry to produce ions from a sample to be analyzed. It is a variant of electrospray ionization.^[1] The sample (for instance a few microlitres of blood or urine) is applied to a piece of paper and solvent is added. Then a high voltage is applied, which creates the ions to be analyzed with a mass spectrometer. The method, first described in 2010,^[2] is relatively easy to use and can detect and measure the presence of various substances in the sample. This technique shows great potential for point-of-care clinical applications, in that important tests may be run and results obtained within a reasonable amount of time in proximity to the patient in a single visit.^[3] In 2017 it was reported that a test based on paper spray ionization mass spectrometry can detect cocaine use from a subject's fingerprint.^[4] It was also used to detect pesticides from the surfaces of fruits.^[5]

More recently, an advanced form of Paper Spray, termed Paper Arrow, was developed. This universal approach seamlessly hyphenates Paper Chromatography and Mass Spectrometry, facilitated by on-paper ionization without requiring visual indicators. The entire process of Paper Arrow was shown to be simple and fast, requiring only 2 μL of raw biological sample. Its analytical performance is in accordance with stringent clinical guidelines, and it demonstrated superior figures of merit compared to LC-MS.^[6]

References

^ Meher, Anil Kumar; Chen, Yu-Chie (2017). "Electrospray Modifications for Advancing Mass Spectrometric Analysis". Mass Spectrometry. 6 (Spec Iss): S0057. doi:10.5702/massspectrometry.S0057. PMC 5448333. PMID 28573082.
^ Liu, Jiangjiang; Wang, He; Manicke, Nicholas E.; Lin, Jin-Ming; Cooks, R. Graham; Ouyang, Zheng (2010-03-15). "Development, characterization, and application of paper spray ionization". Analytical Chemistry. 82 (6): 2463–2471. doi:10.1021/ac902854g. PMID 20158226.
^ Damon, Deidre E.; Davis, Kathryn M.; Moreira, Camila R.; Capone, Patricia; Cruttenden, Riley; Badu-Tawiah, Abraham K. (2016-02-02). "Direct Biofluid Analysis Using Hydrophobic Paper Spray Mass Spectrometry". Analytical Chemistry. 88 (3): 1878–1884. doi:10.1021/acs.analchem.5b04278. ISSN 0003-2700. PMID 26730614.
^ Glatter, Robert (September 23, 2017). "New Fingerprint Test Can Detect Cocaine Use In Seconds". Forbes.
^ Soparwalla, Santosh; Tadjimukhamedov, Fatkhulla K.; Wiley, Joshua S.; Ouyang, Zheng; Cooks, R. Graham (2011). "In situ analysis of agrochemical residues on fruit using ambient ionization on a handheld mass spectrometer". Analyst. 136 (21): 4392–4396. doi:10.1039/C1AN15493A. PMID 21892448.
^ Zhou, Yufeng; Sham, Tung-Ting; Boisdon, Cedric; Smith, Barry; Blair, Joanne; Hawcutt, Daniel; Maher, Simon (2024). "Emergency diagnosis made easy: matrix removal and analyte enrichment from raw saliva using paper-arrow mass spectrometry". Analyst. 148 (21): 5366–5379. doi:10.1039/D3AN00850A.